1. Field of the Invention
The present invention relates to an X-ray analyzer, such as an X-ray fluorescent analyzer.
2. Description of Related Art
In recent years, the Earth's environmental problems have deteriorated increasingly and become more complicated. In response to these global environmental problems, the European Union (EU) has issued a Directive on Waste Electrical and Electronic Equipment (WEEE) and a Directive on the restriction of the use of certain hazardous substances (ROHS). The EU has sounded an alarm by legislating the hazardness. The substances which have been limited in use by the ROHS are 6 substances, i.e., cadmium (Cd), lead (Pb), mercury, hexavalent chromium, poly-brominated biphenyl (PBB), and poly-brominated diphenylether (PBDE).
Components used in electric and electronic devices distributed today are mostly made of plastics. These plastics contain cadmium and lead that are banned from use by the ROHS directive. Accordingly, in recent years, it has become necessary to precisely measure the amounts of cadmium and lead contained in plastics.
With the existing analytical apparatus, however, trace amounts of cadmium from several ppm to tens of ppm contained in plastics cannot be analyzed precisely. Furthermore, if an X-ray fluorescent analyzer that is one kind of analytical apparatus is used, accurate analysis results have not been obtained because of the backgrounds of the X-ray spectra derived by X-ray fluorescent analysis. In particular, the background level of such a spectrum of a trace amount of cadmium is considerably high compared with spectral peaks. That is, the peak/background ratio (P/B) is considerably low.